2tanx + tan^2x + tan^3x +2cotx + cot^x +cot#x = 8

0.43.

Step-by-step explanation:

The probability that the customer will pay with debit card = 50%

The percentage of customers who use coupons 30% and  35% pay with debit card.

Now calculate the probability  that the same person will use coupon:

P[Uses coupons | Pays with Debit card] = P[Uses coupons and pays with debit card] / P[ Pays with debit card]

= 0.3 * 0.5 / 0.35

= 3/7  or  0.4286 or 42.86%